Process of burning fuel.



No. 791,067. PATENTED MAY 30, 1905.

' J. B. ARCHER.

PROCESS OF BURNING FUEL.

APPLICATION FILED JULY 31. 1903.

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P ATENTED MAY 30, 1905.

J. B. ARCHER. PROCESS OF BURNING FUEL.

APPLICATION FILED JULY 31. 1903.

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No. 791,067. PATENTED' MAY 30, 1905.

J. B. ARCHER.

PROCESS OPBURNING FUEL.

APPLICATION FILED JULY a1. 1903.

3 SHEETS-SHEET 3.

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Patented May 30, 1905.

PATENT OFFICE.

JOHN B. ARCHER, OF KENSINGTON, MARYLAND.

PROCESS OF BURNING FUEL.

SPECIFICATION forming part of Letters Patent No. 791,067, dated May 30,1905.

Application filed July 31, 1903. Serial No. 167,724.

To all whom it may concern.-

Be it known that I, JOHN B. ARCHER, a citizen of the United States,residing at Kensington, in the county of Montgomery and State ofMaryland, have invented certain new and useful Improvements in Processesof Burning Fuel, of which the following is a specification.

This process of burning fuel is especially designed to effect thecomplete combustion of solid fuel, such as bituminous coal, in thefurnaces of steamboilers, heating plants, and other apparatus consuminga large amount of fuel.

The process enables the heat units of the fuel to be fully utilized, theproducts of combustion delivered to the stack being substantially freefrom unburned gases, smoke, soot, and cinders.

The process involves the delivery of air to the ignited fuel, especiallyto the gases rising from a bed of coal lying on the grate of a firebox,from different directions and along lines substantially tangent to acircle. The jets of air strike the fuel-gases and set them into rapidrotation, effecting a thorough mixture of the gases and air. Thecentrifugal action caused by the rotary or cyclonic movement of themixed gases and air throws anyheavier unburned particles outward againstthe hot walls of the fire-box, where they are quickly consumed.

The process may be carried out by apparatus of widely-differentconstruction. A furnace which has been found especially useful for thepurpose is shown in the accompanying drawings, in which Figure 1 is avertical longitudinal section on line I I of Fig. 2. Fig. 2 is ahorizontal section on line II II of Fig. 1. Fig. 3 is a transversevertical section on line III III of Fig. 1 looking toward the front ofthe furnace. Fig. 4 is a detail horizontal section through one side ofthe fire-box on line IV IV of Fig. 3. Fig. 5 is a plan view, partly insection, of the air-box removed from the furnace; and Figs. 6, 7, 8 areelevations of the front, rear, and side sections of the air-box,respectively.

For the sake of completeness the furnace is here shownas arranged toheat a steamboiler 1 of well-known construction. The process isobviously capable, however, of general use. The furnace shown comprisesa rectangular fire-box 2, provided with the usual grate 3, ash-pit 4,doorways for fuel 5, having doors 6, and ash-pit doors 7. A shortdistance above the grate and embedded in the brick walls of the fire-boxis the air-box S. This air-box, as shown in Figs. 5, 6, 7, 8, is forconvenience made in several sections of cast iron, steel, or othersuitable material. The ends of the sections are flanged and boltedtogether. The side sections 9 10 are each an integral casting, thesection 10 being provided with an air-inlet 11. The front portion of theair-box consists of two separate arched sections 12 13 and the rearportion of two separate sections 14 15. Projecting from the inner wallsof the air-box are a number of twyers 16, spaced at about equaldistances from each other and arranged in superposed series, the twyersof the upper series being intermediate those of the lower series.

Each of the twyers is arranged to deliver a stream of air in a linesubstantially tangent to a horizontal central circle 17, as indicated bythe dotted lines in Fig. 5, the twyers of the arched sections beingslightly inclined downward to effect this result. This arrangementcauses the jets of air injected through the twyers to strike the gasesrising from the fuel and set them into rapid rotation within thefire-box, effecting a thorough mixture of the gases and air. Thecentrifugal action caused by the rotary or cyclonic movement .of themixed gases and air throws any heavier particles such as those of theunburned gases-outward against the hot walls of the fire-box. Bricks ortiles 18, preferably consisting of a mixture of graphite and fire-clay,project inwardly from the side walls of the re-box above the air-box.These projections soon become incandescent when the furnace is inoperation and cause any unburned fuel-gases which are thrown intocontact with them to be immediately burned. The inner faces of theair-box are protected from the excessive heat by triangular or othertiles 19 of fire-clay or by any other suitable means. Air may besupplied to' the airbox through inlet 11 by means of a valved pi e 20.Hot air may be supplied through a va ved pipe 21, leading from a seriesof heating-coils 22, arranged beneath the rear portion ofthe boiler 1 inosition to be heated by the outgoing pro ucts of combustion. Thesections of the air-box are provided with dampers 23, having handles 24.One of these dampers isshown in position within the air-box in Fig. 5.The dampers enable the volume of air delivered from the various sectionsto be regulated. It is sometimes desirable in operation to decrease theamount of air injected at the front of the fire-box. The greaterquantity of air issuing from the twyers at the rear tends still furtherto hold the gases within the fire-box until they are completely burned.The cyclonic movement within the fire-box is also so controlled as toprevent the too rapid and direct escape of the gases rising from thefuel over the bridge-wall, the gases being thus held within the fire-boxuntil all the combustible matter is consumed and the heat completelyutilized in the generation of steam. The products of combustion escapingto the stack pass off as a light gray vapor containing substantially nosmoke, soot;or unburned fuel-gases.

When the doors of the ordinary boiler-furnace are opened to permitcharging, the inrush of cold air is so great as to temporarily chill thefire-box and boiler-shell and tubes down to a temperature where thecarbon in the gases is deposited as soot, which is afterward swept outby the products of combustion, causing clouds of black smoke to beemitted from the stack. This result is practically overcome by thecyclonic movement within my fire-box. If necessary, the amount of airsupplied through the twyers may be so great as to cause a slight plenumwithin the fire-box, entirely preventing the admission of air throughthe doors. suflicient air-pressure is maintained in the fire-box whenstoking to substantially equal the exterior airressure.

To prevent co d air from striking the boiler or other object to beheated, the fire-clay or tile lining 25 beneath each of the arched sections 12- 13 is extended rearwardly over the grate for some distance,providing shelves 26. These shelves act as baffles and cause any airthat might enter through the doors to pass into the rotating mixture ofgas and air. The shelves are preferablyperforated with numerous smallopenings 27, through which a sufficient amount of the=hot gases passesto keep the shelves at a high temperature and prevent de osit of soot.

Smal test-pipes 28, such as one-half-inch gas-pipe, extend from eachside of the air-box at about the middle along the top of the airbox andout through the furnace-wall at some convenient point, such as thefront,

In practice just where they are provided with valves 29. These pipesserve to withdraw portions of air from different sections of theair-box, so that the pressure or temperature of the air within anyparticular section may be tested by applying a gage or thermometer tothe outer end of the corresponding test-pipe. The supply of air from thedifferent sections is then suitably regulated by means of the dampers23.

The area of the air-inlet 11 should be somewhat greater than thecombined areas of all of the twyers, thus keeping the air under thedesired pressure within the air-box and maintaining a substantiallyuniform pressure at each twyer.

I claim- 1. The process of burning solid'fuel, which consists indelivering streams of air into an unobstructed space above a bed of theignited fuel, the air being introduced from different directions andalong lines substantially tangent to a circle, thereby producing acyclonic movement in the gases rising from the fuel, as set forth. 7

2. The process of burning solid fuel, which consists in passing air upthrough a bed of the ignited fuel, and simultaneously delivering streamsof air into an unobstructed space above the bed of ignited fuel, fromdifferent directions and along lines substantially tangent to a circle,thereby producing a cyclonic movement in the gases rising from the fueland throwing unburned particles outward against the hot walls of thefire-box, as set forth.

3. The process of burning solid fuel lying ona grate, which consists inpassing air up through a bed of the ignited fuel, simultaneously forcingair into the gases rising from the fuel, from diflerent directions andalong lines substantially tangent to a horizontal circle, and separatelyregulating the amount of air delivered from different directions toprevent the escape of any unburned gases, as set forth.

4. The process of burning solid fuel, which consists in deliveringstreams of air from a body of compressed air into an unobstructed spaceabove a bed of the i nited fuel, the air being introduced from differentdirections- JOHN B. ARCHER.

Witnesses:

EUGENE A. BYRNEs, C. A. NEALE.

